Chevy express 2005 Simon

Hi and TIA for your help as I am about to trow the towel, and trow the van to the junk on that probably very cheap small problem.
OK, Chevy express 2500- 2005, 280 000 kms.

2 years ago it begin to have this problem, almost once per month totally randomly, it do not restart after I parked the van for 10 or 30 minutes. It crank clean and do not want to start at all, look like no fuel to injector or no power to injector. Trying to start the minute right after never worked as well. Waiting 10 minutes and starting worked ALL THE TIME. I keep the key ON for the 10 minutes as I red that online. Once or twice I saw the padlock security light came ON and OFF during those 10 minutes.

Later, like 6 months ago, it begin to stall randomly on the road while driving, very dangerous. and you guess it: it start like new after sitting 10 minutes. I don't see the padlock security light on those event. But starting clean or not at all, and starting always after sitting like 10 minutes and never after 2 minutes bring my focus on the security passlock system.

Took off the key cylinder and cleaned it. no change. I shook the wires around, nothing, did not find the modul of this security system.

I bring it to the Chevy dealer and he test run it 30 minute, told me its all good and there is no code so he cannot do nothing.
There is a good amount of power steering fluid leaking from a long time on the fuse box under the hood. Small tiny quantity inside the box.

Yesterday when parked and the van not starting again, I took off and clean the key cylinder, and unplugged and plug back the small 3 wires on a single plastic plug, the security system wire to the magnet. The padlock light came ON and still ON now, and the van worked like it should so far with the light ON. But I haven't drove much since with the light ON as Im affraid it will stall.

Please please please help!